The Cancer Center "Cell and Tissue Imaging Core Facility" (previously the "Confocal Core Facility") is entering its sixth year of operation. Its mission, as developed by the Cancer Center Executive Committee, is to provide advanced cell and tissue imaging technology, services, and scientific consultation that facilitate scientific interaction and enhance scientific productivity of Cancer Center investigators. The Facility was originally developed as a partnership with the Doheny Eye Institute; the partner institutes jointly purchased a 5th generation confocal microscope and housed the instrument in an existing electron microscopy imaging facility adjacent to the Cancer Center. The Facility is jointly managed by the Cancer Center and the Doheny Eye Institute. The 2,000 square foot laboratory space for this shared facility is provided by the Doheny Eye Institute at no cost to the Cancer Center. The Facility is therefore used 50% by the Cancer Center and 50% by Doheny Eye Institute. All funds requested in this proposal are for costs directly related to the Cancer Center's 50% use of the facility. The primary users of this shared resource facility are Cancer Center investigators with peerreviewed, funded projects. The Facility is also open to other Cancer Center members who need its facilities to develop pilot project data. Since its establishment, the Facility has provided the Cancer Center membership with easy access to "state-of-the-art" cell and tissue imaging equipment and technical support. Daytime usage of the confocal microscope remains heavy (90% utilization of available hours); approximately 50% of this usage comes from Cancer Center members (consistent with the 50:50 use arrangement with Doheny Eye Institute). Importantly, the range of imaging equipment and services available to Cancer Center members has expanded (beyond laser scanning confocal/multiphoton microscopy) to include full access to transmission electron microscopy (TEM), scanning electron microscopy (SEM), digital light and fluorescence microscopy, fluorescence and bright field laser capture microdissection, thin sectioning, cryo-sectioning and embedding procedures, and computer aided graphics. We are continuously upgrading our imaging software and advising and instructing Cancer Center investigators in novel methodologies and protocols to enhance their cell and tissue imaging capability.